What is the main purpose of Sodium Fluoride as an additive?

Sodium fluoride serves a crucial role in the preservation of glucose levels in blood samples. Its primary function as an additive is to inhibit glycolytic action, which refers to the breakdown of glucose by cells. During the process of glycolysis, glucose can be rapidly consumed by cells, leading to a decrease in the measured glucose concentration in the blood specimen over time. By inhibiting this process, sodium fluoride helps to stabilize the glucose levels in a sample, ensuring that laboratory results accurately reflect the patient's glucose status at the time of collection.

In clinical settings, this is particularly important when testing for glucose, as accurate readings are essential for diagnosing and managing conditions like diabetes. Thus, the presence of sodium fluoride in blood collection tubes helps maintain the integrity of glucose measurements by minimizing the interference caused by cellular metabolism.